Railway-traffic-controlling apparatus



R. A. McCANN. RAILWAY-TRAFFIC CONTROLLING APPARATUS.

APPL lCATIO N FILED NOV. 4| I920? Patented 'Feb 21, 1922.

2 SHEETQ-SHEET l- IN V EN TOR.

ML; ATTORNEY.

R. A. MpCANN. RAILWAY TRAFFIC CONTROLLING APPARATUS.

' APPLICATION FILED 'NOV. 4, 1920.

Patented Feb. 21, 1922.

2 SHEETS-SHEET 2..

SEW

INVENTOR ca/vvvv Ma ATTORNEY.

track circuit comprisinga battery b"a'nd'a Age T craze 3SWITCH-& SIGNAL COMPANY, or swIssvALn: PE NSYL ANIA, *A -coRPme TION OF PENNSYLVANIA.

RAILWAY-TRAFFIC-CONTROLLING APPARATUS.

T 0 all whom it may concern;

Be'it known that I, RONALD AfMcGANN, a citizen of the United States, residing"at Swissvale, in the county of Alleghenyand State of Pennsylvania, have invented certain new and useful Improvements in Railway TraflicControlling Apparatus, of which the following is a specification. My "invention relates to railway trafiio controlling'apparatus, and particularly to apparatus of the'type comprisingsignals which are controlled, at least in part, by

point out the novel features thereof in claims. D

In the accompanying draw1ngs,'F1g; 1 is a view, largely diagrammatic,*showing one form of apparatus embodying'my invention, and Fig. 2 1s a view' similar-t0 Fig. 1 but showing a'modifiedform of apparatus'also embodying my invention.

' Similar reference charactersxrefer to sim ilar parts in each of the views. 'Referring first to Fig. 1, the reference characters '2 and '2 designatethe two rails of a railway track R over which trafiic-normally moves in the direction indicated by the arrow. These rails are divided by'insulated jointse to form a] stretch of track A- -H,

"which'I will call'the interlocking block, and

a preliminary or approach section The block AH*may comprise'any desired number of insulated track sections, only one such section being shown in the drawin'g'to simplify the disclosure. This section is provided with' a track circuit comprising a track battery 5 and aQtra'ck relay T, and the approach section is similai'lyprovided with-a track relay T. V

Traffic into the block A-LH" is governed by a signal S comprisinga high ormainarm 4, and an auxiliary or callingon arm o. Each of these'a'rn s normally occupies a horizontal position as shown in' the drawing,

wherein it indicates stop, buteach'arm I I H device "or lockcomprisin'g'a se ment "9 atmay be moved to an inclined position where- Specification ofIietters Patent.

seetion'is "as" far as possibl in it indicates proceed, the inainarm when in such positiongiv ng' a high. speedindica-' tion and the calling-on arm a low speed in-;-

PatcritedfFbfZl, i'c'22. Application filed November 4, 1920;: Serial no.421',e'7e. f I

indication or a warning that the block 'ii H; is probably occupied. The manner in which signal S is controlled 'will' be explained in detail hereinafter.

"The approach section H'C.fis jgprovided witlra signal S which is controlled jointl by trackrelay T and by-arinl of signal so that this signal indicates stop when section'H C is occupied,caution when such signal S conform with standard and well understoodpractice,fland' form no part of Trackrelay T.- controlsa relayD -which unoccupied'iand arm 4 is'at stop, and proceed whense ction He-c is unoccumy 'invei'ition,'ancl hence theyare omitted from the drawing to simplify the disclosure is known as an"approach locking relay, the

control being such that relay D; is closedor open according as'r'elayT is closed or open. {the circuit for relay D isfrom the terminal B ofa suitablesource of current, through contactfi of relay T, wire 7, winding ofrelay D,"tof' terin'inal O of thesaine source of current. I 7 I 'Signal Sis conti'o'll e'd jointly by? track relay T iorthe stretch 6r track A H, and by a manually operable lever Lp. The lever L;

is one of a plurality of leversin'aninterlocking machine, which levers govern Vfll'l OHS Switches signals, etc, controlling tr f c through the block AH. Thi '1 i the form hereshown, "is mounted to svvingon its longitudinal axis, and isprovided with a handle'8 to facilitate' manual operation.

"The lever ,jnor nally occupies a position "whereinthe handle is vertical, and when n such position'both armsof'signal S are atv 'stop {the lever may be swung fromitsinormal position to clear arm 4 or 5, according to trafiic conditions within the block as willhereinafter appear, and in' act u'al practice it usually may also swing toithe drawing.

:right to clear another 'sign'al whichfgovei s trafiic 'i'novin'g towards the right th ugh block A H' butwhi'ch is; net shown in the The lever L is controlled antached to the lever and provided with a dog 10. Coactmg; with this dog 1s a latch 11 having at its upper end. a horizontal which rests on the dog when the lever is in the normal or middle position. lVhen the lever is swung in one direction or the other, however, the latch falls by gravity into the path of the dog 10, so that the lever can then be returned only part way to its normal position, that is, to a right hand or a left hand indicating position. The lever can be returned to its full normal position only after a magnet 12 has been energized to attract its armature 11 and so to raise opened as soon as this lever is lTlOFGll toward the left. It follows that when relay E is die-energized it can become energized only if track relay T is closed and lever L is in the normal position. T acl: relay T is closed only when the bloclr.zil-l is unoccupied. If this bloclrconrprises more than one track circuit, then, in accordance Wlll usual practice, the pick-up circuit for relay E Wlll include a contact of each track relay in the block, these contacts being included in series in the circuit for relay E. ltelay E is provided with a holding circuit which passes from terminal 13 through contact 13 'oftrack relay T, wire lei, winding of rela E, wires 15 and 18, contact of relay E, to terminal 0 of the same source of current. It follows that after relay E once becomes energized, it will remain energized even though lever L be subsequently swung to the left, but will become deenergized as soon as a train enters the block ii il.

The main arm a of signal S is provided with a circuit which is controlled jointly by the automatic release relay E and by lever L. This circuit passes from terminal B of' a suitable source of current, through contact 20 of lever L, wire 21, contact 22 of relay E, wire 23, operating mechanism for signal arm 4:, and wire 24 to terminal O .ofthe same source of current. l Contact 20 1 is closed only when lever L is swung to the :full left hand position.

S to move to the proceed or clear position by swinging lever L to the extreme left.

The lever L cannot, thereafter, be eturned 1 to'its'full normal position until magnet 12 trolled hand release F.

is energized, although it may be returned at any time to its left hand indicating position wherein contact 20 is open, so that arm l of signal S returns to its stop position.

I will now assume that the main arm 1 of signal S has been cleared and that a train has entered the blockQL-H. This train, of course, opens track relay T, which in turn tie-ener izes relay E, thereby opening the circuit for arm 4; at contact 22, so that this arm returns to'the stop position. lriagnet 12 then becomes energized by virture of a ircuit which passes from terminal B' 'of a suitable source of c rrent, through contact 25 operated by signal S. and closedwhen this signal is in the stop or caution position, wire 26, contact 2? operated by signal arm 5, and closed only when such arm is in the stop position, wire 2S, contact 29 operated by signal arm i and closed only when'such arm is in the stop position, wires 30 and $1, back contact of relay IE, wire 33, contact 34- operated in the manner hereinafter explained, wires and 35", contact 36 opera ed by lever L, wire 3'7, and magnet winding 12, to terminal of the same source of current; Contact 36 is closed when lever L is in the extreme left hand position or in the left hand indicating position, or at any'pointbetween these two positions. The circuit just traced is what is known as the automatic release. circuit, and it will be seen that when it is closed, it permits the operator to return lever L to the normal position, thereby releasing other levers which control routes conflicting with the route governed by signal S.

it sometimes necessary to return lever L to the normal position-after'arm l has been cleared and befor a train has entered the block l iH. if there is no train in the ap proach section H-C, the lever may be re.- leased by what is known as the appro: locking circuit.

39, contact 40 of approach locking relay D,-

wires. 41,42, 35, contact36, wire 3'7, and

magnet winding 12, to terminal of the same source of current. This circuit is what is known as the approach locking circuit, and it permits the return of lever L to the normal position before train has entered section HC- r It is also sometimes necessary to return lever L to the normal position while a train occupies the approach section H C, and to permit this the approach locking circuit for magnet 12 is provided with a time conllhis release 30221 prises a cont-act which normally. opened,

but which maybe :closed by'a manual operaer than i tion H- C. -yllhen'the contact of the release "F iSClQSGClylt closes'a-branch around contact .140 of relay D, which branch passes from wire 88 through ire l3,the.contaet of the release F, andwire e4 to wire i2. It follows,'tl1erefore, that even though relay D is open, due to the .presence'oi't'a-train in sectiouH U,

the release ma net 12': ma wbe enere'ized to c i Q position.

Asstated hereinbefore, thelever L is one of a. plurality of similar levers-in an interlocking machine, some ofwhich levers control switches and others of which control signals.- 'When lever L is in its extremeleft 7 hand position v or in its extreme leit'hand incheating position, it looks in normal. position all other levers governing routes which in anyway conflict with the route-governed by "signal S; It is essential, therefore; that the means hereinbeforedescribed should be provided' forpreventing' the "return lever! L to its full normal position, .exceptiunder pre -=determined conditions. 'Irwill now assume that whilethe block err-H is occupied by the train which has'been wadmitted in the manner hereinbefore exolained; theloperator desires to permit a sec 'ond train-moving in the direction to enter this block. To do -this,'he leaves lever L in'thelei t'hen'd position, or returns it to -suchposition i1" it-has been restored-to normal; position, and then/presses a: pushbutton Pinwardly. 'This operation'of the pushbutton closes a eontact and opens Contact The closing. of contact cuit forthe calling-ion arm e, whichcircuit isfromr terminal-B eta suitable source of current, through contact 45," wire elhc'oneact at? on lever L,-wire 4;8, contacte opera ed ,by -main arm"t and closed-onlywhen t f :arm is instop-position,-wire.=50, opei atil -n1eohanism for and wirefl'a to termi al ()"of'the same source oi current. been arm 5 then moves to the proceedrposition, thereby advising theengineer'of'a t llo train that' he; may'enter the block V 7 "low speedfexpecting to find the bloclrcceupied; v r

Push-button? is'so located in the interlocking; machine that it is directly'behind ha-ndleb when leverL normal'position. it :iollo TS, therefore, thatthis button-"can be operate-d only when thelev'er has been swung "to the left or to the right. "fThis'but-ton' is, furthermore, controlled in 'the following manner. The shank 'f'the button is provided witha sl1eulden5].,;ancl-a dog 52 is jpressedgupwar 13; against this shoulder by a spring 53. When I the 1 button 1 is ipu'sh'ed in,

permit lever L to be'returned to 'itsuniddle 15 closes a cirthe dog 52'llS8S,{LII1C leP the'influe'nce o'f the springinto lockingposition at the leftend ofshoulderfil, and solo'cks the button in the operated position 'To release "the button, the dog 52 provided with a-t'appet 541 the lower end of which straddles' the button shank and is attachedto thedog, and the upper end of which carries a roller 54* eoaeting with n cam 55 fixed to the shaft of lever I L; This'cam is so shap'edithat the tappet' exerts no influence on dog 52 when lever L 18 in either extreme position or either 1nd1. catlngi'position, but't-hat when the lever -1s pet is drivendownwardly-sci pushthe dog restored to the full normal position the tapout of the path of shoulder-51, whereupon f the push button 'returns to'thenormal positionunder the influence of a spring 56.

It will be seen from 'theforegoing that when button P has once'been operated,-it-

cannot-bere'stored until lever has' be'en returned to thenormal position. But when the button P is in the operated position,-c0n

tact84 is open so that the automatic means for releaslng lever 11 1s inefl'eetlve, that 1s,

Y the circuit branchthrough' back contact 32 of relay E cannot be used to energize magnet 12. The fact that relay"E is open' due to the presenee of the first train in block does not,'then, permit lever -Lto be' released by the automatic means, button the 1 other *handthis lever can be released'only-by the approach loclri'rrg means'" or by the slow-- actin'g hand release F In {other =w0rds,

= when :the calling-on arm 5 has been clearedf 1 lever i L cannot fibe -released to permit i a con passed signal S;,- except by, operation 0f reilease "F, the time element of 1 which is, of

course, greater than the time normal'lyconsinned; by ,Ca train" in passing through i appreach sectioniHC Referri-ng" now to 'F-ig. 2,2 the circuit 5 for the control of theimain-arm {i of'signal- S is the same as in Fig. 1; llhe'circ'u'its for" the release "of leverLafter this main arm has "been cleared are likewise; the same; as the corresponding; CTICLfIHlZfS in Fig. 1, except that the ZLUt'OHIZLtIC" release circuit controlledby relay E includes 'a baekcOntactB P -Ot a' re lay-"J,- in place cfithemontact M of 'F-ig. 1.

from terminal B through contact 62, wire 57, winding of relay J, wires 58 and (SO, and contact 61 of relay J, to terminal U of the same source of'current. It follows, therefore, that when relay J is once energized, it'

will remain energized until lever L is returned to the normal position.

The circuit for the calling-on arm 5 passes from terminal 13 of a suitable source of current, through'contact a? on lever L, wire 63, contact-45 of relay J, wire 48, contact 49, wire 50, operating mechanism of signal an 5, and wire 2a to terminal 0 of the same source of current. This calling-on arm can be cleared, therefore, when relay 5 is 8116? gized and lever L is in the extreme left hand position. After the calling-on arm is thus clearedit may be returned to the stop position by returning lever L to the left hand indicating position, but the lever cannot be restored to its full normal position after a train has accepted signal S except by operation of the slow-acting hand release F. The important feature of the apparatus shown in Fig. 2 is that when the calling-on arm 5 has been cleared, the automatic release circuit controlled by relay E is ineffective owing to the fact that contact '34? is open, so that the presence of a preceding train in block A-H does not permit lever L to be returned to the normal position.

Although I have herein described only two forms of apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described myinvention, what I claim is: 1

1. Railway traffic controlling apparatus comprising a block, a signal governing traffic into said block and having a main arm and a calling-on arm, a manually operable lever for controlling said signal and having a normal position in which both of said arms indicate stop, means controlled by said lever when moved to an operated position for clearing said main arm, a lock for preventing return of said lever to normal position, approach locking means for releasing said lock except when there is a train approaching said block and automatic means for releasing said look when a train has entered said block, an auxiliary manual- 1y controlled device having a normal position and acting to clear said calling-on arm 'whenthe device and the lever are both in operated positions, and means for prevent ing return of said device to normal position until the lever has been restored to. normal position; characterized by the combination therewith of means associated with said auxiliary device and functioning when the :device is in operated position to prevent refor preventing return of said lever to normal position, approach locking means for releasing said lock except. when there is a train approaching said block and automatic means for releasing said lock when a train has entered said block, an auxiliary manually controlled device having a normal position and movable to an operated position when said lever is in the operated position, means for clearing said calling-on arm when said lever and said device are both in operated position, and means for preventing return of said device to normal position until the lever has been restored to normal position; characterized by the combi nation therewith of means associated with said auxiliary device and functioning when the device is in operated position to prevent release of said lever look by said automatic means. V

3. Railway traffic controlling apparatus comprising a block, a signal governing traflic into said block and having a; main arm and a calling-on arm, a manually operable lever for controlling said signal and having a normal position in which both of said arms indicate stop, means controlled by said lever when moved to an operated position. for clearing said main arm, a lock for preventing return of said lever to normal position, approach locking means for releasing said lock except when there is a train approaching said block and automatic means for releasing said lock when a train has entered said block, an auxiliary manually controlled device comprising a contact and having a normal position in which said contact is open, said device being movable to an operated position in which said contact is closed when the lever is in operated position, 'means forpreventing return of said device to normal position until the lever has been restored to normal position, and means for clearing said calling-on arm when said lever is in operated position and said contact is closed; characterized by the combination therewith of a second contact actuatedby said auxiliary device and functioning when the device is in operated position to prevent release of said lever look by said automatic means.

4:. Railway traffic controlling apparatus comprising a. block, a signal governing traffic into said. block and having a main said lever when moved to an operated posi-- tion for clearing said main arm, a look for preventing return of said lever to normal position, approach locking means for releasing said lock except when there is a train approaching said block and automatic means for releasing said look when a train has entered said block, a normally open relay, means for closing said relay when said lever is in operated position and for subsequently keeping the relay closed until the lever is restored to normal position,

means for clearing said calling-0n arm when 1 said relay is closed and said lever is in operated position, and means for preventing release of said lever look by said automatic means when said relay is closed,

In testimony whereofl afiix my signature.

RONALD A. MCOANN. 

